Experimental results on the fission of doubly and other multiply charg
ed metal clusters are reviewed and examined in the light of a simple m
odel, where the fission barrier is approximated as two charged spheres
in near-contact, at a mutual distance given by the balance between Co
ulomb repulsion and attractive polarization effects. The barriers are
estimated for different mass and charge splits and are compared with t
he activation energy for the competing evaporation process. From the m
odel as well as in experiment one finds a strong preference for singly
charged trimers (with two electrons) in the ''fission'' channel, but
also fragments with the higher magic electron numbers 8 and 20 may occ
ur with enhanced abundance. In addition, there is a pronounced odd-eve
n effect. In most of the experiments that have been carried out so far
, fission occurs as the termination of a chain of evaporations of neut
ral atoms. This limits the observations to a range where the surface e
nergy dominates over the Coulomb energy of the fissioning cluster, exp
laining the tendency for asymmetric fission and justifying the two-sph
ere barrier approximation. Conditions favoring symmetric fission and o
ther fission modes specific to highly charged metal drops are discusse
d, and experimental approaches are suggested.